This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 119e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2026-05-20

3191. Reference collapsing with pack indexing and splicing

(From submission #903.)

Subclause 9.3.4.3 [dcl.ref] paragraph 7 was not updated when pack indexing and splicing was added to the language. And neither was paragraph 1.

Possible resolution:

1. Change in 9.3.4.3 [dcl.ref] paragraph 1 as follows:

   ... Cv-qualified references are ill-formed except when the cv-qualifiers are introduced through the use of a typedef-name (9.2.4 [dcl.typedef], 13.2 [temp.param]) or decltype-specifier (9.2.9.6 [dcl.type.decltype]) computed-type-specifier (9.2.9.3 [dcl.type.simple]), in which case the cv-qualifiers are ignored. ...

2. Change in 9.3.4.3 [dcl.ref] paragraph 7 as follows:

   If a typedef-name (9.2.4 [dcl.typedef], 13.2 [temp.param]) or a decltype-specifier (9.2.9.6 [dcl.type.decltype]) computed-type-specifier (9.2.9.3 [dcl.type.simple]) denotes a type TR that is a reference to a type T, an attempt to create the type “lvalue reference to cv TR” creates the type “lvalue reference to T”, while an attempt to create the type “rvalue reference to cv TR” creates the type TR. ...